Not sure I am interpreting the question correctly, but it sounds like you are talking about needing to auto-fit the height of an AreaType object to its text content, so as to accommodate different lengths of text that are imported into the bound textFrame variable.
Unlike better text handling in other programs, Illustrator textFrame objects do not provide a vertical auto-fit capability to avoid overset text.
There have been several attempts to script a workaround for the long-needed auto-fit capability. Mine is referenced in
this thread.
The alternative would be to use a PointType object as the bound textFrame, and include carriage returns in your dataset values.
JET